The phrase "about fourfold" is correct and usable in written English.
It can be used when discussing a quantity or measurement that is approximately four times greater than another.
Example: "The population of the city has increased by about fourfold over the last decade."
Alternatives: "approximately four times" or "roughly four times".
The difference in average per capita disposable income between rural and urban areas was about fourfold.
Moreover, only luminal AE activity increased about fourfold over the control in the presence of 5 μ m forskolin.
Together with the about fourfold reduced rates of 1,2-GDN formation measured in ascorbate-deficient aortas (see Table 2), these results indicate that ascorbate deprivation interferes specifically with GTN bioactivation.
Substituting the pyridine group of 3 with the thiazole group of 9 increased UVA phototoxicity in HaCaT and A2780cis cells, and increased blue visible light phototoxicity in HaCaT cells by about fourfold.
"He has helped change the entire financial outlook of the foundation and increased assets about fourfold," Dr. Waxman said of Mr. Nierenberg's eight years in the foundation's post.
While FitzSimons has said publicly that ARM membership has multiplied about fourfold in the past year or so (mostly since his appointment last July), he is cagey about talking, publicly at least, about precise numbers.
BLOOMBERG NEWS Buyout Firms Flockck to Indonesia | Private equity firms focused on Indonesia have increased their fund-raising about fourfold from 2010, according to the Center for Asia Private Equity Research in Hong Kong, Bloomberg News reports.
The efficacy of 5E-4-hydroxy-DHA 2a as a PPARγ activator was about fourfold stronger than that of pioglitazone.
It was reported that, following SLN dispersion, dye penetration increased by about fourfold over the uptake obtained following cream application.
The reducing sugar produced by XYL7-TC was about fourfold greater than that produced by their parents when incubated with xylan at 60 °C for 4 h.
Systemic administration resulted in the highest increase in potency, being about fourfold, while spinal and local administration increased potency in two- and threefold, respectively.
